Lost 4WD transfer, Cruise Control, AC Blower fan at same time. Cannot find cause on 2004 GMC Sierra 2500 HD

The other day I was driving my truck and I was attempting to assist a friend stuck in ice by pulling him out. When I got there I was unable to put my truck in 4WD. The button signals that it is attempting to and I can hear the transfer servo engaging but it never reports being in 4WD. I later found that I couldn't engage my Cruise Control same day and the next morning my heater fan wouldn't run and being in Alaska it was pretty cold :)

I can't guarantee that it was all at the same time but I use all of these features often and it wouldn't have taken long to notice.

I have checked the obvious fuses and they are all intact. I am unsure if there is a relay that handles all three systems or not. I have pulled my engine codes and I have two U1000, C0035, and P0101.

The U1000 is likely my information cluster as it is currently dead. I need to replace it or the cable connecting it but I am not certain since it is a generic error.

The C0035 is my in tire speed sensor and that is only causing my speed gauge to be off by 10%

The P0101 is my K&N filter and this is apparently common.

Thanks in advance for any assistance.

Asked by for the 2004 GMC Sierra 2500 HD
1 answer
scan all modules for codes and post so we can adv. could be related to several malfuntioning systems